Certificateless Signature Scheme Based on Rabin Algorithm and Discrete Logarithm

Certificateless signature can effectively immue the key escrow problem in the identity-based signature scheme. But the security of the most certificateless signatures usually depends on only one mathematical hard problem, which makes the signature vulnerable when the underlying hard problem has been broken. In order to strengthen the security, in this paper, a certificateless signature whose security depends on two mathematical hard problems, discrete logarithm and factoring problems, is proposed. Then, the proposed certificateless signature can be proved secure in the random oracle, and only both of the two mathematical hard problems are solved, can the proposed signature be broken. As a consequence, the proposed certificateless signature is more secure than the previous signatures. On the other hand, with the pre-computation of the exponential modular computation, it will save more time in the signature signing phase. And compared with the other schemes of this kind, the proposed scheme is more efficient

A Computationally Efficient Online/Offline Signature Scheme for Underwater Wireless Sensor Networks

Underwater wireless sensor networks (UWSNs) have emerged as the most widely used wireless network infrastructure in many applications. Sensing nodes are frequently deployed in hostile aquatic environments in order to collect data on resources that are severely limited in terms of transmission time and bandwidth. Since underwater information is very sensitive and unique, the authentication of users is very important to access the data and information. UWSNs have unique communication and computation needs that are not met by the existing digital signature techniques. As a result, a lightweight signature scheme is required to meet the communication and computa‑ tion requirements. In this research, we present a Certificateless Online/Offline Signature (COOS) mechanism for UWSNs. The proposed scheme is based on the concept of a hyperelliptic curves cryptosystem, which offers the same degree of security as RSA, bilinear pairing, and elliptic curve cryptosystems (ECC) but with a smaller key size. In addition, the proposed scheme was proven secure in the random oracle model under the hyperelliptic curve discrete logarithm problem. A se‑ curity analysis was also carried out, as well as comparisons with appropriate current online/offline signature schemes. The comparison demonstrated that the proposed scheme is superior to the exist‑ ing schemes in terms of both security and efficiency. Additionally, we also employed the fuzzy‑based Evaluation‑based Distance from Average Solutions (EDAS) technique to demonstrate the effective‑ ness of the proposed scheme.publishedVersio

An Efficient Certificate-Based Designated Verifier Signature Scheme

Certificate-based public key cryptography not only solves certificate revocation problem in traditional PKI but also overcomes key escrow problem inherent in identity-based cryptosystems. This new primitive has become an attractive cryptographic paradigm. In this paper, we propose the notion and the security model of certificate-based designated verifier signatures (CBDVS). We provide the first construction of CBDVS and prove that our scheme is existentially unforgeable against adaptive chosen message attacks in the random oracle model. Our scheme only needs two pairing operations, and the signature is only one element in the bilinear group G1. To the best of our knowledge, our scheme enjoys shortest signature length with less operation cost

Efficient identity based signcryption scheme and solution of key-escrow problem

In cryptography for sending any information from sender to receiver, we have to ensure about the three types of security policies i.e. integrity, confidentiality and authentication. For confidentiality purpose, encryption-decryption technique is used and for authentication purpose digital signature is used, so to ensure this three properties, first sender encrypt the message and then sign the message. Same process done at the receiver end that means first message is decrypted then verified, so it's two step process that increases the communication as well as computation cost. But in many real life applications where more speed and less cost is required like e-commerce applications, we can't use signature then encryption technique, so signcryption is the cryptographic primitives that provides signature as well as encryption at the same time on a single step. First signcryption scheme is proposed by Yullian Zheng in 1997, Since then many signcryption scheme is proposed based on elliptic discrete logarithm problem (ECDLP) , Bilinear pairing, Identity Based and certificateless environment. Many of the Signcryption scheme used Random Oracle Model for their security proofs and few are based on standard model

A Comprehensive Survey on Signcryption Security Mechanisms in Wireless Body Area Networks

WBANs (Wireless Body Area Networks) are frequently depicted as a paradigm shift in healthcare from traditional to modern E-Healthcare. The vitals of the patient signs by the sensors are highly sensitive, secret, and vulnerable to numerous adversarial attacks. Since WBANs is a real-world application of the healthcare system, it’s vital to ensure that the data acquired by the WBANs sensors is secure and not accessible to unauthorized parties or security hazards. As a result, effective signcryption security solutions are required for the WBANs’ success and widespread use. Over the last two decades, researchers have proposed a slew of signcryption security solutions to achieve this goal. The lack of a clear and unified study in terms of signcryption solutions can offer a bird’s eye view of WBANs. Based on the most recent signcryption papers, we analyzed WBAN’s communication architecture, security requirements, and the primary problems in WBANs to meet the aforementioned objectives. This survey also includes the most up to date signcryption security techniques in WBANs environments. By identifying and comparing all available signcryption techniques in the WBANs sector, the study will aid the academic community in understanding security problems and causes. The goal of this survey is to provide a comparative review of the existing signcryption security solutions and to analyze the previously indicated solution given for WBANs. A multi-criteria decision-making approach is used for a comparative examination of the existing signcryption solutions. Furthermore, the survey also highlights some of the public research issues that researchers must face to develop the security features of WBANs.publishedVersio

A Study on the Secure Online Examination System

13301甲第4475号博士（工学）金沢大学博士論文本文Full 以下に掲載：IJCANDI (International Journal of Computing and Informatics) 1(3) pp.90-100 2016. Universitas Mulawarman & Universiti Malaysia Sabah. 共著者：Abdul Wahid, Masahiro Mamb

Certificateless Public Key Signature Schemes from Standard Algorithms

Certificateless public key cryptography (CL-PKC) is designed to have succinct public key management without using certificates at the same time avoid the key-escrow attribute in the identity-based cryptography. However, it appears difficult to construct CL-PKC schemes from standard algorithms. Security mechanisms employing self-certified key (also known as implicit certificate) can achieve same goals. But there still lacks rigorous security definitions for implicit-certificate-based mechanisms and such type of schemes were not analyzed formally and often found vulnerable to attacks later. In this work, we first unify the security notions of these two types of mechanisms within an extended CL-PKC formulation. We then present a general key-pair generation algorithm for CL-PKC schemes and use it with the key prefixing technique to construct certificateless public key signature (CL-PKS) schemes from standard algorithms. The security of the schemes is analyzed within the new model, and it shows that the applied technique helps defeat known-attacks against existing constructions. The resulting schemes could be quickly deployed based on the existing standard algorithm implementations. They are particularly useful in the Internet of Things (IoT) to provide security services such as entity authentication, data integrity and non-repudiation because of their low computation cost, bandwidth consumption and storage requirement

새로운 무인증서 공개키 배포 방법과 경량 보안 연결 방법

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2017. 2. 권태경.Authenticating the other endpoint and protecting the data communication are the basic and important ways of secure communication. As the penetration of the Internet to the everyday life is getting accelerated, e.g. Internet of Things (IoT), the demand of secure communications increases. However, the aforementioned two ways have been threatened due to the problems of the Public Key Infrastructure (PKI) and the constrained resources of IoT devices. Therefore, this dissertation focuses on enhancing authentication regarding public key distribution and data protection considering resource-limited IoT devices. First, the current PKI has problems like certificate revocations and fraudulent certificates. To address such issues, we propose TwinPeaks, which is a new infrastructure to distribute public keys of named entities online. TwinPeaks leverages certificateless public key cryptography (CL-PKC), which we extend to make the public key of an entity depend on any combination of its networking parametersthus TwinPeaks can mitigate spoofing attacks systematically. TwinPeaks needs public key servers, which constitute a hierarchical tree like Domain Name System (DNS). For each parent-child link in the tree, the parent and the child interact in such a way that every named entity has its own public/secret key pair. TwinPeaks removes certificates and hence has no revocation overhead. Instead, each named entity should keep/update its IP address and public key up-to-date in its DNS server and key server, respectively. TwinPeaks also achieves scalable distribution of public keys since public keys can be cached long term without elevating security risks. Next, the IoT will be the norm in the foreseeable future. However, the security problem in the Internet will be worsened in IoT services considering the constrained resources of IoT devices. We propose a delegation-based DTLS/TLS framework (D2TLS) for cloud-based IoT services. D2TLS aims to achieve mutual authentication and to lower the burden of setting up secure connections significantly while keeping the private keys of IoT devices secret. Leveraging the session resumption in the DTLS/TLS standard and introducing a security agent, D2TLS achieves these goals with the modifications only within the IoT domain. That is, cloud and PKI systems need no change to deploy D2TLS. Numerical results show that D2TLS can achieve better performance in terms of delay and energy consumption than making a DTLS/TLS connection in standalone mode.1. Introduction 1 1.1 Motivation 1 1.2 Research Contributions 2 1.3 Organization of Dissertation 3 2 TwinPeaks: A New Approach for Certificateless Public Key Distribution 4 2.1 Introduction 4 2.2 Design Rationale 6 2.3 Certificateless Public Key Cryptography (CL-PKC) 8 2.4 How TwinPeaks Works 10 2.4.1 TwinPeaks Overview 11 2.4.2 CL-PKC extension 14 2.4.3 Public Key Update 16 2.4.4 Public Key Caching 17 2.4.5 Deployment: Islands & TLS Variant 18 2.5 Security Analysis 19 2.5.1 Threat Analysis 19 2.5.2 Certificateless Validation of a Public Key 21 2.6 Evaluation 22 2.6.1 Qualitative Comparison 22 2.6.2 Quantitative Comparison 23 2.6.3 Numerical Results 27 2.7 Discussions 33 2.8 Related Work 36 3 D2TLS: Delegation-based DTLS for Cloud-based IoT Services 38 3.1 Introduction 38 3.2 Related Work 41 3.3 Measurement of IoT Products 43 3.3.1 Smart Home Monitoring System 43 3.3.2 Smart Watch 48 3.4 Delegation-based DTLS (D2TLS) 51 3.4.1 D2TLS Framework 53 3.4.2 End-to-End Secure Connection 55 3.5 Security Considerations 56 3.6 Evaluation 59 3.6.1 Evaluation Environments 59 3.6.2 Delay 61 3.6.3 Energy Consumption 63 3.6.4 Code Size and Memory Requirements 65 3.6.5 Expected Session Overhead varying Frequency and Lifetime of a Session 66 3.7 Discussion 68 3.7.1 IoT device as a Server 68 3.7.2 Hardware-assisted IoT Security 69 4 Conclusion 71 Bibliography 73 초록 79Docto

Cryptographic Schemes based on Elliptic Curve Pairings

This thesis introduces the concept of certificateless public key cryptography (CLPKC). Elliptic curve pairings are then used to make concrete CL-PKC schemes and are also used to make other efficient key agreement protocols. CL-PKC can be viewed as a model for the use of public key cryptography that is intermediate between traditional certificated PKC and ID-PKC. This is because, in contrast to traditional public key cryptographic systems, CL-PKC does not require the use of certificates to guarantee the authenticity of public keys. It does rely on the use of a trusted authority (TA) who is in possession of a master key. In this respect, CL-PKC is similar to identity-based public key cryptography (ID-PKC). On the other hand, CL-PKC does not suffer from the key escrow property that is inherent in ID-PKC. Applications for the new infrastructure are discussed. We exemplify how CL-PKC schemes can be constructed by constructing several certificateless public key encryption schemes and modifying other existing ID based schemes. The lack of certificates and the desire to prove the schemes secure in the presence of an adversary who has access to the master key or has the ability to replace public keys, requires the careful development of new security models. We prove that some of our schemes are secure, provided that the Bilinear Diffie-Hellman Problem is hard. We then examine Joux’s protocol, which is a one round, tripartite key agreement protocol that is more bandwidth-efficient than any previous three-party key agreement protocol, however, Joux’s protocol is insecure, suffering from a simple man-in-the-middle attack. We show how to make Joux’s protocol secure, presenting several tripartite, authenticated key agreement protocols that still require only one round of communication. The security properties of the new protocols are studied. Applications for the protocols are also discussed